Electromagnetic brake mechanism.



W. D. LUTZ.

ELECTROMAGNETIC BRAKE MEGHANISM. APPLIOATION FILED DBO. 9, 1909.

Patented July '7, 1914.

UNITED STATES PATENT OFFICE.

WILLIAM J L u'rlz, or ALLENDALE, NEW Jnnssvfnssrsnon To oTiIsELEvA'roR COMPANY, or JERSEY crrx, NEW :rnnsnm n conromrron on NEW JEnsEY.

smcrnomeenn'rxc BRAKE MECHANISM:

Specification of-Letters Patent. A ppllicatien flled December 9, 1909. "serial No sealer Patented July .7, 191 4..

To all whom it may concern:

. Be it known that I wanna DJ Lama I citizen of the United btates, and residing 1n into and out of frictional contact with the brake pulley 5 keyed to a'shaft 6 which may the borough of Allendale, in the county of Bergen and State of New Jersey, have 1nvented a new and useiiul Improvement in.

is deenergized to permit the brakes to be applied;v

It has'been found in practice that with brake apparatus of the type herein shown, the residual magnetism is sometimes su-fii- "cient to prevent the-brake springs from im-' mediately applying the brakes. when the magnet is deenergized; This objection 1s overcome in the present invention by the use of stifi coil springs which are compressed during the final movement of the magnet 'armatiires toattracted position, the tenslon on these springs being ample to overcome any residual magnetism. These'sprigigs at the same time overcome any tendency of either armature to move pastithe center, and

they also prevent the slamming noise ordi-.

narily present inothe use of electrdmagnets of thetypeshown. p

In the accompanying drawings is shown a 'form of brake apparatus embodying the present invention.-

The brake mechanism is supported by a frame Aunouhted on a base B. Brake levers 1 are pivoted at 2 to the frame A. Brake shoes 3 are pivotally connected at 4 tothe brake levers and are adapted to be moved be a motor shaft, or the shaft of a hoisting drum, or other apparatiis to which the brake inechanismis applied. The brake shoes are "applied by means ofcompression springs 7 which bear at their inner endsagainst annular shoulders 8 formedonthe brake shoes. Theouter ends of the' brake springs 7 extend into stationary cup-shaped bearingmemloers 9 which may be adjustably secured. to the frame A by means of bolts 10.

A11 electromagnet M for releasing .the'

85 brake shoes is mounted uponthe frame A,

and as herein shown, is adapted to be ener gizedchya'multiphase elLectric current. This magnet. comprises a casing 11 having end plates 12 secured thereto. A stationary sleeve 13 extends longitudinally through the center of the magnet casing, and has its ends countersunk in the end: plates 12. The mag-- net comprises a plurality of stationary coils 1f]: wound, on spools 15 which are held statlonary by clamp washers 16 mounted on the sleeve 13. The magnet armatures comprise end plates or disks 17 slidable on the sleeve 13 and 'Iaminated' cores l8 -secured tothe end plates and adapted to enter the spools 15. 7

Pivoted at 19 to the upper ends of. the brake levers are horizontal rods 20 extendln-g into the sleeve 13. The armatures are secured to these rods 20 by pins 21 which-- extend through longitudinalopenings 22 in the sleeve 13, these openings permitting the armatures to move in a horizontal direction; Mo'un-ted: on the rods 20 are stiff coil springs 23 adapted to bear, attheir inner ends, against the outer faces of the'fend plates 12 of the magnet frame, and at their outer ends against washers 24 interposed between said springs and shoulders 25 formed on. the rods 20'. The spring 23 areof such 'length that they are only com-pressed during the final'm'ovement of the magnet armatures toward their'attracted'position. The washers 24 form a convenient means of adjustment whereby any desired tension of the springs 23 may be secured.

- When the magnet M is deenergized' the brake springs 1 hold the 'brake-shoes against the brake pulley 5. At this'time the springs 23- are loose on the rods 20 there being some.

play between these springsfand the magnet frame. When the magnet is energized the "ax-matures 17 are pulled-- inward, thereby operating the br'ake levers to com-press the brake springs '7' and lift the brake shoes. During the initial rio'vement of the brake levers the springs 23 re not compressed,but-

as the armatures approach each other" and are brought intoa position to exert a POWBI: fu lmagneticpull, the springs 23 are compressed, and are held under compression until the brake magnet is-aga-in deenergized, at which time the tension of the springs is suflicient to effectually overcome any stickingdile. to residual magnetism independently ofthe main brake springs 7 These springs also: prevent eitheramnature from moving farther than the other, which sometimes happens when these springs arenot used, in such case the armatures-may be brought.

'. together with only one brake shoe released.

The springs 23 furthermore serve to reduce or entirely eliminate the loud slamming noise that usually occurs in the operation of an alternatingjcurrent magnet of this type owing to its quick and powerful action when energized. a

The resent invention, although shown in combination with brake'apparatus, is also 4 well adapted for use with electro-magnets for operating electric switches and various other mechanisms. The-invention may also be applied to singlephase 'alternatingcurrent magnets and direct currentmagnets.-

I wish further not to be limited-to the particular constr11ction='herein shown, 'as various vchanges in the details of construction and arrangement of parts might be made without departing from the spirit and scope of the invention. e v e f" 'What I claiin as new and desire to secure by Letters Patent of the United States is 1. In brake apparatus, the combination with an electro-magnet, of an armature therefor, an elastic stoplimiting the inward movement of the armature, said stop being inert'at the beginning to-periorm its "1ntend ed function and under compression at the final movement of the armatureto attract 6 ed position} and brake mechanism connected to said armature.

2.. In brake apparatus, the combination withan electro-magnet, of an armature with an e'lectro-magnet'and its armature, of

' beginning to perform their intended tune- 'tions and. under compression at the final a brakefspring' opposing the movement of the armature toward its attracted position, and an additional spring inert at the beginning to perform its intended function and under compression at the final movement of the tion.

with brake shoes, of brake applying springs,

an. electromagnet comprising magnet cores movable toward and from each other, connections between said cores and said brakeshoes, and additional springs inert at the movement of said magnet cores toward at tr-acted position.

5. In brake apparatus, the combination brake. apparatus, the combination armature toward attracted 'posi- 4.-In brake apparatus, the combination with an eledtro-magn'et having its, winding in a stationary or fixed positiognof armatures associated with said winding and movable toward and away from each other, I

elastic means under tension to perform their. intended function when the armatures are in attracted position and limiting the movemen-tent of the armatures toward each other and compelling each to move through sub-- stantially the same distance, and brakemechanis'm connected to the armatures.

6. In brake apparatus, the combination with an alternating, current electromagnet with its winding in stationary or fixed position, of armatures associated with said winding and movable toward and away from each other, brake applying springs, means for limiting the. movement of said armatures toward .each other to compel each to move through. substantially the same distance, said means being placed under ten- --s1on when the armatures are in thelr at tracted posit on, brake shoes, and connections between the brake shoes and said armatures. a

- I 7. In brake. apparatus, the" combination with a multiphase alternating current electromag'net having windings mounted in stationary or fixed position, of armatures movable toward. each otherupon excitation of said windings, springs opposing said movement, additional springs for cushioning said movements of the armatures and compelling them each, to move through substantially the same distance, said springs being,

under tension to perform their intended function. when the armatures are in their attracted; position, and brakes operatively connected to said armatu'res'.

8. In brake apparatus, the combination with a multiphase alternatingcurrent elec tromagnet having windingsmounted in sub-- stantially fixed or stationary-position, of

armatures acted upon-by said windings when excited with electric'current to move toward each other, elastic devices-retarding and then positively limiting the inward movements of -said armatures, appliances for retracting said armatures "to initial posi tions when said windings are unexcited, brake devicesfxnd connections between said devices and the armatures.

9.In bralze apparatus, the combination with a multiphase alternating current electroma'gnet having windings mounted in stationary or fixed pos1t-1on,.of armatures movable toward and away from each other, ap-

pliances for, retarding the movements of the armatures toward each other, means for positively limiting the last-named movements, brake apparatus released upon the excitation of said windings, and means for applying said brake apparatus and retracting said armatures when said windings are u nexcited.

10, In brake apparatus, the combination with a brake, of an electromagnet for releasing the brake,.means for overcoming residual magnetism andefl'ecting 'an initial 5 movement of the brake toward applied position when'the electfomagnet is denergized and additional means for applying the brake.

. 11. In brake apparatus, the combination with a brakejmember, of a brake applyingsprmg, an 'electromagnetcomprising a mov-.

able member connected to said brake member for movingthe latter to released position,

and a still spring normally inert to perform its intended function but placed under ten sion by the movable member of'the magnet during its final movement toward attracted position.- V 1 j.

12., In brake apparatus, the combination with an electromagnet,.of an armature there- 20. for, an elastic stopine'rt to perform its intended function at the" beginning of the inward movement of the armature and limit-i ing said inward movement, brake mechanism connected to said armature, brake applying. means, and adjusting means to vary the tension placed on said stop. I 13. In brake apparatus, the combination with a support, of brake 'le'vers pivoted to said support, an electromagnet comprising'a magnet frame mounted .on said'support, and armatures connected to the brake levers, brake shoes-carried by the brake levers, a brake pulley, brake springs for applying the brake shoes to said pulley, "and sti springs inert at the "beginning-t0 perform' their intended function and compressed during the final movement of the armatures to attracted position. I -14, The combination with an electro-mag- 40 net, of. an armature therefor, an elastic stop limiting the inward movement of the armature inert. at the beginning to perform its intended function and placed under com pression bVIthe final movement of the armature to attracted position, a spring opposing the entire movement of thearmature t'o attractedposition, a brake, and connection between the brake and armature.

. 15.'Thecombination with 'an electromagnet, of an armature therefonmeans for retracting the armature when the magnet is deenergized, a device for yieldingly oppos-f ing the final movement of the armature toward its attracted osition inert at the beg ing to perform its intended function and placed under compression by said final movewardits attracted position and held'under. tension while the armature is in such atfunctionssand compressed by the final moveinent, and .a brake connected to the armature. 16. The combination with an electromagnet and its armature, of means for with-- drawing the armature when. the mag et is deener'gized, a spring inert at the beginning to perform its intended function and opposmg the final movement of the armature totractedyposition, and brake mechanism con;

nected to the armature. v 1

17. The combination with an electromagnet having itswinding in a stationary or "fixed position, the armatures associated connected to the armatures.

18. The combination with an" alternating current electromagn'et having windings mounted in astationary or fixed position, of armatures m va-ble toward and from each other, springs inert at the beginning to'perforni their intended function and placed under compressionby final movement of thearmatures to attracted position and held under compression while the armatures are in attracted position and brake levers connected to the armatures. V 9

19. The combination with a support, of an electromagnet comprisinga magnet frame mounted on said support, armaturesfor saidfmagnet movable toward and from each other, stifl coil springs associated with said varmatures and in position to be inert at the beginning to perform their intended ment of the armatures to attracted position, and brake mechanism carried by said su port and 'o-perativelv connected to said armatures. I y In testimony whereof, I have signed my name to this specification in the presence of two subscribingwitnesses. I

' WILLIAM D. LUTZ. Witnesses:

AUeUsr SUNDH, ,JoHnF. 

